Vesicular membranes are intimately involved in the storage, transport and release of regulatory and metabolic agents in cellular systems. To function properly these vesicles must be able to actively accumulate these agents, retain them for periods of time and then expel them to an external environment by fusion with a limiting membrane. It is our objective to understand at a molecular level factors which affect the fusion, solute concentration, and solute transport properties of vesicles and to use that understanding in the design of useful artificial analogues. These objectives will be pursued largely through the study of model phospholipid vesicles which contain anionic lipids and in which fusion can be stimulated by the addition of Ca2 ion. However, the studies will also be extended to isolated storage granules in which biogenic amines are concentrated. Nuclear magnetic resonance (nmr) techniques including 1H, 19F, 31P, 13C, and 113Cd nmr will be developed and used in the study of both membrane structure and membrane transport.